Method and apparatus for drawing metal



APPLICATION FILED FEB. 10, I9l9.

Patented Feb. 3,1920.

ATTORNEY PATENT cur os.

LOUIS H. BRINKMAN, OEGLEN' RIDGE, NEW JERSEY, ASSIGNOR TO BALL ROLLEDTUBE CORPORATION, A CORPORATION OF NEW YORK.

1 ME H D AND APPARATUS FOR DRAWING METAL.

To all whom it may concern;

Be it known that I, LOUIS H. BRINKMAN, a citizen of the United States,residingat Glen Ridge, county of Essex, and State of New Jersey, haveinvented new and useful Improvements in Methods and Apparatus forDrawing Metal, of which the following isa specification.

This invention relates to the drawing of metal rods or tubes.

Where the metal to'be drawn is heated in a furnace, particularly wherethe furnace is heated by an oil or gas flame, if the furnace gases flowinto contact with the metal too intense heating of the metal may occuror the heating of the metal may be unevenly distributed or both. This isnotably the case in connection with the drawing of thin tubes. Alsowhere the furnace gases, especially where the furnace is heated by gasor oil flames, are projectedagainst the metal,

'- it is liable to oxidize and form scale, which is most objectionablein the case of thin tubes. i

It is one object of the invention to shield the metal to be drawn frombecoming excessively heated.

It is a further object of the invention to evenly distribute the heatingof the metal.

' It is a further object of the invention to prevent the formation ofscale.

Other and ancillary objects of the invention will appear hereinafter.

While the invention will probably prove most useful when employed in afurnace, it

may have other applications.

In the accompanying drawing which illustrates the invention The figureis a view partly in side elevation and'partly in section of an apparatusembodying the invention and illustrating means whereby the method may becarried out.

Referring to the drawings, 1 is a suitable furnace, which may be heatedby an oil flame, fuel orfuel and airbeing admitted to the interior ofthe furnace by suitable pipes or nozzles 2 and 3. I

Extending through the furnace is a heat distributing and metal shieldingtube 4 of metal having suitable heat capacity. Extending through the"tube 4 is a tube 5 Specification of Letters Patent.

Patented Feb. 3, 1920.

6 Application filed. February 10, 1919. Serial No. 275,939.

to be drawn through the die 6 having a series of balls 7, arrangedcircumferentially of the tube 5 and constituting the members of thediewhich operate upon the'work. The ring 8 circumscribing the balls 7 isrotated by an electric motor 9 and suitable cooling means may beprovided for the die parts. It is unnecessary herein, however, todescribe in further detail the structure of the die or the arrangementof it in conjunction with the motor as such an apparatus is shown anddescribed in my Patent No. 1,203,306, issued October 31st, 1916, andparticularly with reference to Figs. 1 to 8 thereof, this showingincluding a draw bench for draW- ing the tube through the die which maybe used in the apparatus of the present case. Within the tube extends amandrel comprising the tube 10 extending through the furnace and havingsecured at its end a high speed steel head 11 lying. under the balls 7and between which and the balls the tube 18 1 space 16, thus retardingthe communication of heat from the head to the member 12. The member12is of iron or steel of'a less refractory character than that of the head11 and at the high temperatures 'at which it is possible to work thehead 11, the threads in the member 12 whereby the head 11 is secured,would be liable to soften and strip off. Accordingly means is providedfor cooling the member 12'and particularlythe nipple 14 so that itsthreads, will not become sufficiently heated to be distorted, carebeingtaken to prevent the cooling fluid from being dashed against the head11. To this'end the member 12 is provided with a central passage 17which, it will'be observed, does not extend entirely through the member12 to the head, but is separated from the head by a partition 18.Directly opposite the mouth of the passage 17 is the end of a pipe 19which, at its other end is connected; with i a suitable source ofcooling water under suitable I ordinarily be of highly refractorymaterial,

from undue heating in the furnace, it is surrounded by a suitable heatinsulating covering 21. This may be of asbestos which may be maintainedin position by means of an 1nclosing metal sleeve 22. Inasmuch as theoperation of the apparatusdrawing temperature. might become function ofthe sleeve 22 is simply to hold the heat insulation in place, it maysoften to a considerable extent without affecting the w and consequently1s not necessary to be absolutely refractory at the temperature to whichit is subjected within the furnace.

It will be seen that the tube 4 extends beyond the furnace andpractically fills the gap between the furnace and the d1e so that theheat of the tube to be drawn is preserved in its passage from thefurnace to the die so that it i delivered to the latter at the proper-Otherwise the tube unduly cooled, particularly if itisthin.' I

To draw a tube, the mandrel is withdrawn from the rear end of thefurnace. A tube to be drawn is entered within the tube 4 which may then,be heated up1 or may have previously been heated. T e tube 4 imparts itsheat to the tube 5 and when at the proper temperature the latter ispassedthrough the die. It being understood that the mandrel is insertedwith its head under the balls as shown in the drawing and the end of thetube secured to the draw head as described in ing. of the tube over themandrel head he neath the balls effects the desired reduction. After thelength of tube has been drawn through the die, the mandrel may be withdrawn from the rear of the furnace, a new length of tube inserted,heated and drawn as described, and this operation repeated indefinitely.

It will be seen that the tube 4-shields the metal to be drawn from thegases of the furnace so that the formation of scale is mitigated orprevented. Also the hot gases do not beat against the metal so thatdanger of excessive heating, especially of thin tubes, is prevented.Further the conductivity of the metal of the tube 4 causes any heatreceived to tend to distribute itself through the tube so that the heatimparted to the metal to be drawn is more evenlydistributed. Also this Iconductivity causes heat to'be conveyedto l from a tube my patent abovereferred to. ,The drawis "passed, and

which it may be carried out, it is to be unered to thedie under theproper heat condiso that the tube to be drawn derstood that neither theinvention of appa ratus or method of the drawings, to the precisedetails recited.

-WhatIclaimis p 1. The method of drawing metal, which consists incausing it to acquire the desired heat from heated walls between whichit-is passed, and passing it through a reducing .pass.

is limited to the apparatus consists in causing it to acquire thedesired heat from a'heated tube through which itis passed, and passlngit through a reducing pass. I w

3. The method of drawing metal, which consists in causing it to acquirethe desired 2. The method of drawing metal, which nor is the methodlimited heat from heated walls between which it is passed, the saidwalls being heated simultaneously with the passage of the metal, andpasslngthemetal through a reducing pass.

4. The method of drawing metal, which consists'in imparting to it thedesired heat through which the metal is passed, said tube being heatedfrom the exsaid metal and a reducing pass. 5. The method of drawingmetal, which consists in imparting heat to said metal from hot gases,while shieldingit from said' gases and passing the metal through areducing pass. i 6. The method of drawing metal, which consists inheating a heat conductin wall by hot gases, and heating metal to' be,

whereby theheat imparted to said metal is'more uniformly distributed,and passing the heated metal through a reducing ass.

7. In metal drawing apparatus,"t e com- 'bination with wallsbetween-which the metal sired degree by reducing the heated metal.

'terlor simultaneously with the passage of' passing the metal throughrawnby' imparting heat from said wall to said metal,

wherein it is heated to the deheat derived from'said walls,- means forheating said walls and a pass for" 8. In metal drawingapparatus, thecombination with a tube through which the metal ispassed, and wherein itis heated to the .de: sired degree by heat derived from said tube,

means for heating said tube and a pass for[ reducing the heatedmetal.

9. In metal drawing apparatus, the c0m-' bination withafurnace of a tubein said,

furnace through which the metal is adapted to be passed and a pass forreducing the metal. I c

10. In metal drawing apparatus, the combination with a furnace of a tubeextending entirely through said furnace, through which the metal isadapted to be passed and a pass for reducing the metal.

11. In metal drawing apparatus, the combination with a furnace of a tubein said 110 furnacethrough which the metal is adapted to bepassed,'and-a pass for reducing the metal, said tube extending outsidethe furnace into the space between said furnace and I pass. v 15 Intestimony whereof I have signed this specification this 31st day of'January, 1919.

/* LOUIS H. BRINKMAN.

